This invention relates in general to intravascular catheters, such as can be used during minimally invasive surgical procedures. In particular, this invention relates to an intravascular catheter having an expandable incising portion.
Atherosclerosis is a chronic condition in which atheromatous plaque accumulates on the inner walls of a blood vessel. As a result, the blood vessel walls can become inflamed and, over time, may harden to form atherosclerotic lesions that cause a narrowing of the vessel lumen. In severe cases, the atherosclerotic lesions can rupture and induce the formation of thrombus (i.e., blood clots), which can prevent blood flow through the narrowed vessel lumen.
There are known procedures and devices for treating or otherwise reducing the risks associated with atherosclerosis. For example, an angioplasty is a procedure in which a balloon catheter is inserted into a narrowed region of the vessel lumen via a delivery catheter. The balloon catheter includes a flexible tube having an inflatable balloon at an end thereof. Once positioned in the narrowed region, the balloon is inflated in order to dilate the narrowed vessel lumen. The pressure in the balloon is generally sufficient to compress the accumulated plaque. However, compressing the atherosclerotic material requires the use of relatively high inflation pressures. Such angioplasty procedures are typically performed by inflating a balloon to a pressure in the range of 10-20 atmospheres. These high inflation pressures place a strain on the blood vessel walls and on the tissue surrounding the blood vessel, which can result in damage.
In some cases, it would be desirable to score the atherosclerotic material so as to break the surface tension and permit compression to be performed at lower pressures. In some cases, it would be desirable to score the atherosclerotic material so as to fragment the atherosclerotic lesions or permit fragmentation of the same during subsequent angioplasty. Thus, it would be desirable to provide an intravascular catheter having an expandable portion that can be selectively controlled by a user and adapted to create incisions in atherosclerotic material to facilitate the compression or fragmentation of the atherosclerotic material during a subsequent angioplasty procedure.
This invention relates to an intravascular catheter device for use during a surgical procedure. The catheter device includes a catheter tube having an expandable portion with a plurality of struts each defining an outer surface. The expandable portion is operable between a closed position, wherein the expandable portion has a first diameter, and an opened position, wherein the expandable portion has a second diameter that is larger than the first diameter. An incising element is provided on the outer surface of at least one of the struts. The incising element has a sharpened edge that extends outwardly in a radial direction from the outer surface of the strut for creating an incision in atherosclerotic material located within a blood vessel when the expandable portion is in the opened position.
The expandable portion, particularly the incising element and sharpened edge, may be configured to prepare the blood vessel for subsequent angioplasty. The intravascular catheter device may be configured to facilitate the scoring of the atherosclerotic material, which may break the surface tension in the atherosclerotic material and provide for subsequent the compression thereof by angioplasty at reduced pressures relative to traditional procedures. After scoring the atherosclerotic material with the intravascular catheter device, equivalent or improved compression may be achieved at balloon inflation pressures of 1 to 5 atmospheres in exemplary embodiments, though any pressure or any pressure range is contemplated. Scoring the atherosclerotic material with the intravascular catheter device may also facilitate the fragmentation of the atherosclerotic material when scoring or during subsequent angioplasty.
Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.